/*
 * FILE:	sha256.c
 * AUTHOR:	Aaron D. Gifford - http://www.aarongifford.com/
 *
 * Copyright (c) 2000-2001, Aaron D. Gifford
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided w627ith the distribution.
 * 3. Neither the name of the copyright holder nor the names of contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <string.h> /* memcpy()/memset() or bcopy()/bzero() */
#include <assert.h> /* assert() */
#include "sha256.h"

/* discover byte order on solaris */
#if defined(__SVR4) || defined(__sun)
#include <sys/isa_defs.h>
#define BYTE_ORDER _BYTE_ORDER
#endif

/*
 * ASSERT NOTE:
 * Some sanity checking code is included using assert().  On my FreeBSD
 * system, this additional code can be removed by compiling with NDEBUG
 * defined.  Check your own systems manpage on assert() to see how to
 * compile WITHOUT the sanity checking code on your system.
 *
 * UNROLLED TRANSFORM LOOP NOTE:
 * You can define SHA2_UNROLL_TRANSFORM to use the unrolled transform
 * loop version for the hash transform rounds (defined using macros
 * later in this file).  Either define on the command line, for example:
 *
 *   cc -DSHA2_UNROLL_TRANSFORM -o sha2 sha2.c sha2prog.c
 *
 * or define below:
 *
 *   #define SHA2_UNROLL_TRANSFORM
 *
 */


/*** SHA-256/384/512 Machine Architecture Definitions *****************/
/*
 * BYTE_ORDER NOTE:
 *
 * Please make sure that your system defines BYTE_ORDER.  If your
 * architecture is little-endian, make sure it also defines
 * LITTLE_ENDIAN and that the two (BYTE_ORDER and LITTLE_ENDIAN) are
 * equivilent.
 *
 * If your system does not define the above, then you can do so by
 * hand like this:
 *
 *   #define LITTLE_ENDIAN 1234
 *   #define BIG_ENDIAN    4321
 *
 * And for little-endian machines, add:
 *
 *   #define BYTE_ORDER LITTLE_ENDIAN
 *
 * Or for big-endian machines:
 *
 *   #define BYTE_ORDER BIG_ENDIAN
 *
 * The FreeBSD machine this was written on defines BYTE_ORDER
 * appropriately by including <sys/types.h> (which in turn includes
 * <machine/endian.h> where the appropriate definitions are actually
 * made).
 */
#if !defined(BYTE_ORDER) \
		|| (BYTE_ORDER != LITTLE_ENDIAN && BYTE_ORDER != BIG_ENDIAN)
#error Define BYTE_ORDER to be equal to either LITTLE_ENDIAN or BIG_ENDIAN
#endif

/*** SHA-256/384/512 Various Length Definitions ***********************/
/* NOTE: Most of these are in sha2.h */
#define SHA256_SHORT_BLOCK_LENGTH (SHA256_BLOCK_LENGTH - 8)
#define SHA384_SHORT_BLOCK_LENGTH (SHA384_BLOCK_LENGTH - 16)
#define SHA512_SHORT_BLOCK_LENGTH (SHA512_BLOCK_LENGTH - 16)


/*** ENDIAN REVERSAL MACROS *******************************************/
#if BYTE_ORDER == LITTLE_ENDIAN
#define REVERSE32(w, x)                                                  \
	{                                                                    \
		sha2_word32 tmp = (w);                                           \
		tmp = (tmp >> 16) | (tmp << 16);                                 \
		(x) = ((tmp & 0xff00ff00UL) >> 8) | ((tmp & 0x00ff00ffUL) << 8); \
	}
#define REVERSE64(w, x)                                \
	{                                                  \
		sha2_word64 tmp = (w);                         \
		tmp = (tmp >> 32) | (tmp << 32);               \
		tmp = ((tmp & 0xff00ff00ff00ff00ULL) >> 8)     \
			  | ((tmp & 0x00ff00ff00ff00ffULL) << 8);  \
		(x) = ((tmp & 0xffff0000ffff0000ULL) >> 16)    \
			  | ((tmp & 0x0000ffff0000ffffULL) << 16); \
	}
#endif /* BYTE_ORDER == LITTLE_ENDIAN */

/*
 * Macro for incrementally adding the unsigned 64-bit integer n to the
 * unsigned 128-bit integer (represented using a two-element array of
 * 64-bit words):
 */
#define ADDINC128(w, n)             \
	{                               \
		(w)[0] += (sha2_word64)(n); \
		if((w)[0] < (n)) {          \
			(w)[1]++;               \
		}                           \
	}

/*
 * Macros for copying blocks of memory and for zeroing out ranges
 * of memory.  Using these macros makes it easy to switch from
 * using memset()/memcpy() and using bzero()/bcopy().
 *
 * Please define either SHA2_USE_MEMSET_MEMCPY or define
 * SHA2_USE_BZERO_BCOPY depending on which function set you
 * choose to use:
 */
#if !defined(SHA2_USE_MEMSET_MEMCPY) && !defined(SHA2_USE_BZERO_BCOPY)
/* Default to memset()/memcpy() if no option is specified */
#define SHA2_USE_MEMSET_MEMCPY 1
#endif
#if defined(SHA2_USE_MEMSET_MEMCPY) && defined(SHA2_USE_BZERO_BCOPY)
/* Abort with an error if BOTH options are defined */
#error Define either SHA2_USE_MEMSET_MEMCPY or SHA2_USE_BZERO_BCOPY, not both!
#endif

#ifdef SHA2_USE_MEMSET_MEMCPY
#define MEMSET_BZERO(p, l) memset((p), 0, (l))
#define MEMCPY_BCOPY(d, s, l) memcpy((d), (s), (l))
#endif
#ifdef SHA2_USE_BZERO_BCOPY
#define MEMSET_BZERO(p, l) bzero((p), (l))
#define MEMCPY_BCOPY(d, s, l) bcopy((s), (d), (l))
#endif


/*** THE SIX LOGICAL FUNCTIONS ****************************************/
/*
 * Bit shifting and rotation (used by the six SHA-XYZ logical functions:
 *
 *   NOTE:  The naming of R and S appears backwards here (R is a SHIFT and
 *   S is a ROTATION) because the SHA-256/384/512 description document
 *   (see http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf) uses this
 *   same "backwards" definition.
 */
/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */
#define R(b, x) ((x) >> (b))
/* 32-bit Rotate-right (used in SHA-256): */
#define S32(b, x) (((x) >> (b)) | ((x) << (32 - (b))))
/* 64-bit Rotate-right (used in SHA-384 and SHA-512): */
#define S64(b, x) (((x) >> (b)) | ((x) << (64 - (b))))

/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */
#define Ch(x, y, z) (((x) & (y)) ^ ((~(x)) & (z)))
#define Maj(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))

/* Four of six logical functions used in SHA-256: */
#define Sigma0_256(x) (S32(2, (x)) ^ S32(13, (x)) ^ S32(22, (x)))
#define Sigma1_256(x) (S32(6, (x)) ^ S32(11, (x)) ^ S32(25, (x)))
#define sigma0_256(x) (S32(7, (x)) ^ S32(18, (x)) ^ R(3, (x)))
#define sigma1_256(x) (S32(17, (x)) ^ S32(19, (x)) ^ R(10, (x)))

/* Four of six logical functions used in SHA-384 and SHA-512: */
#define Sigma0_512(x) (S64(28, (x)) ^ S64(34, (x)) ^ S64(39, (x)))
#define Sigma1_512(x) (S64(14, (x)) ^ S64(18, (x)) ^ S64(41, (x)))
#define sigma0_512(x) (S64(1, (x)) ^ S64(8, (x)) ^ R(7, (x)))
#define sigma1_512(x) (S64(19, (x)) ^ S64(61, (x)) ^ R(6, (x)))

/*** INTERNAL FUNCTION PROTOTYPES *************************************/
/* NOTE: These should not be accessed directly from outside this
 * library -- they are intended for private internal visibility/use
 * only.
 */
void SHA512_Last(SHA512_CTX *);
void SHA256_Transform(SHA256_CTX *, const sha2_word32 *);
void SHA512_Transform(SHA512_CTX *, const sha2_word64 *);


/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
/* Hash constant words K for SHA-256: */
const static sha2_word32 K256[64] = {0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL,
		0xe9b5dba5UL, 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
		0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL,
		0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL,
		0x0fc19dc6UL, 0x240ca1ccUL, 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL,
		0x76f988daUL, 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
		0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL, 0x27b70a85UL,
		0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL, 0x650a7354UL, 0x766a0abbUL,
		0x81c2c92eUL, 0x92722c85UL, 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL,
		0xc76c51a3UL, 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
		0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL,
		0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL,
		0x84c87814UL, 0x8cc70208UL, 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL,
		0xc67178f2UL};

/* Initial hash value H for SHA-256: */
const static sha2_word32 sha256_initial_hash_value[8] = {0x6a09e667UL,
		0xbb67ae85UL, 0x3c6ef372UL, 0xa54ff53aUL, 0x510e527fUL, 0x9b05688cUL,
		0x1f83d9abUL, 0x5be0cd19UL};

/* Hash constant words K for SHA-384 and SHA-512: */
const static sha2_word64 K512[80] = {0x428a2f98d728ae22ULL,
		0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
		0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL,
		0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
		0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL, 0x72be5d74f27b896fULL,
		0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
		0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL,
		0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
		0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL, 0x983e5152ee66dfabULL,
		0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
		0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL,
		0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
		0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL, 0x650a73548baf63deULL,
		0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
		0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL,
		0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
		0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL, 0x19a4c116b8d2d0c8ULL,
		0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
		0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL,
		0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
		0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL, 0x90befffa23631e28ULL,
		0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
		0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL,
		0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
		0x113f9804bef90daeULL, 0x1b710b35131c471bULL, 0x28db77f523047d84ULL,
		0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
		0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL,
		0x6c44198c4a475817ULL};

/* Initial hash value H for SHA-384 */
const static sha2_word64 sha384_initial_hash_value[8] = {0xcbbb9d5dc1059ed8ULL,
		0x629a292a367cd507ULL, 0x9159015a3070dd17ULL, 0x152fecd8f70e5939ULL,
		0x67332667ffc00b31ULL, 0x8eb44a8768581511ULL, 0xdb0c2e0d64f98fa7ULL,
		0x47b5481dbefa4fa4ULL};

/* Initial hash value H for SHA-512 */
const static sha2_word64 sha512_initial_hash_value[8] = {0x6a09e667f3bcc908ULL,
		0xbb67ae8584caa73bULL, 0x3c6ef372fe94f82bULL, 0xa54ff53a5f1d36f1ULL,
		0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL, 0x1f83d9abfb41bd6bULL,
		0x5be0cd19137e2179ULL};

/* Initial hash value H for SHA-512/256 */
const static sha2_word64 sha512_256_initial_hash_value[8] = {
		0x22312194FC2BF72CULL, 0x9F555FA3C84C64C2ULL, 0x2393B86B6F53B151ULL,
		0x963877195940EABDULL, 0x96283EE2A88EFFE3ULL, 0xBE5E1E2553863992ULL,
		0x2B0199FC2C85B8AAULL, 0x0EB72DDC81C52CA2ULL};

/*
 * Constant used by SHA256/384/512_End() functions for converting the
 * digest to a readable hexadecimal character string:
 */
static const char *sha2_hex_digits = "0123456789abcdef";


/*** SHA-256: *********************************************************/
void sr_SHA256_Init(SHA256_CTX *context)
{
	if(context == (SHA256_CTX *)0) {
		return;
	}
	MEMCPY_BCOPY(
			context->state, sha256_initial_hash_value, SHA256_DIGEST_LENGTH);
	MEMSET_BZERO(context->buffer, SHA256_BLOCK_LENGTH);
	context->bitcount = 0;
}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-256 round macros: */

#if BYTE_ORDER == LITTLE_ENDIAN

#define ROUND256_0_TO_15(a, b, c, d, e, f, g, h)                      \
	REVERSE32(*data++, W256[j]);                                      \
	T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[j] + W256[j]; \
	(d) += T1;                                                        \
	(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c));                    \
	j++


#else /* BYTE_ORDER == LITTLE_ENDIAN */

#define ROUND256_0_TO_15(a, b, c, d, e, f, g, h)           \
	T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[j] \
		 + (W256[j] = *data++);                            \
	(d) += T1;                                             \
	(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c));         \
	j++

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

#define ROUND256(a, b, c, d, e, f, g, h)                       \
	s0 = W256[(j + 1) & 0x0f];                                 \
	s0 = sigma0_256(s0);                                       \
	s1 = W256[(j + 14) & 0x0f];                                \
	s1 = sigma1_256(s1);                                       \
	T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[j]     \
		 + (W256[j & 0x0f] += s1 + W256[(j + 9) & 0x0f] + s0); \
	(d) += T1;                                                 \
	(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c));             \
	j++

void SHA256_Transform(SHA256_CTX *context, const sha2_word32 *data)
{
	sha2_word32 a, b, c, d, e, f, g, h, s0, s1;
	sha2_word32 T1, *W256;
	int j;

	W256 = (sha2_word32 *)context->buffer;

	/* Initialize registers with the prev. intermediate value */
	a = context->state[0];
	b = context->state[1];
	c = context->state[2];
	d = context->state[3];
	e = context->state[4];
	f = context->state[5];
	g = context->state[6];
	h = context->state[7];

	j = 0;
	do {
		/* Rounds 0 to 15 (unrolled): */
		ROUND256_0_TO_15(a, b, c, d, e, f, g, h);
		ROUND256_0_TO_15(h, a, b, c, d, e, f, g);
		ROUND256_0_TO_15(g, h, a, b, c, d, e, f);
		ROUND256_0_TO_15(f, g, h, a, b, c, d, e);
		ROUND256_0_TO_15(e, f, g, h, a, b, c, d);
		ROUND256_0_TO_15(d, e, f, g, h, a, b, c);
		ROUND256_0_TO_15(c, d, e, f, g, h, a, b);
		ROUND256_0_TO_15(b, c, d, e, f, g, h, a);
	} while(j < 16);

	/* Now for the remaining rounds to 64: */
	do {
		ROUND256(a, b, c, d, e, f, g, h);
		ROUND256(h, a, b, c, d, e, f, g);
		ROUND256(g, h, a, b, c, d, e, f);
		ROUND256(f, g, h, a, b, c, d, e);
		ROUND256(e, f, g, h, a, b, c, d);
		ROUND256(d, e, f, g, h, a, b, c);
		ROUND256(c, d, e, f, g, h, a, b);
		ROUND256(b, c, d, e, f, g, h, a);
	} while(j < 64);

	/* Compute the current intermediate hash value */
	context->state[0] += a;
	context->state[1] += b;
	context->state[2] += c;
	context->state[3] += d;
	context->state[4] += e;
	context->state[5] += f;
	context->state[6] += g;
	context->state[7] += h;

	/* Clean up */
	a = b = c = d = e = f = g = h = T1 = 0;
}

#else /* SHA2_UNROLL_TRANSFORM */

void SHA256_Transform(SHA256_CTX *context, const sha2_word32 *data)
{
	sha2_word32 a, b, c, d, e, f, g, h, s0, s1;
	sha2_word32 T1, T2, *W256;
	int j;

	W256 = (sha2_word32 *)context->buffer;

	/* Initialize registers with the prev. intermediate value */
	a = context->state[0];
	b = context->state[1];
	c = context->state[2];
	d = context->state[3];
	e = context->state[4];
	f = context->state[5];
	g = context->state[6];
	h = context->state[7];

	j = 0;
	do {
#if BYTE_ORDER == LITTLE_ENDIAN
		/* Copy data while converting to host byte order */
		REVERSE32(*data++, W256[j]);
		/* Apply the SHA-256 compression function to update a..h */
		T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + W256[j];
#else  /* BYTE_ORDER == LITTLE_ENDIAN */
		/* Apply the SHA-256 compression function to update a..h with copy */
		T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + (W256[j] = *data++);
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
		T2 = Sigma0_256(a) + Maj(a, b, c);
		h = g;
		g = f;
		f = e;
		e = d + T1;
		d = c;
		c = b;
		b = a;
		a = T1 + T2;

		j++;
	} while(j < 16);

	do {
		/* Part of the message block expansion: */
		s0 = W256[(j + 1) & 0x0f];
		s0 = sigma0_256(s0);
		s1 = W256[(j + 14) & 0x0f];
		s1 = sigma1_256(s1);

		/* Apply the SHA-256 compression function to update a..h */
		T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j]
			 + (W256[j & 0x0f] += s1 + W256[(j + 9) & 0x0f] + s0);
		T2 = Sigma0_256(a) + Maj(a, b, c);
		h = g;
		g = f;
		f = e;
		e = d + T1;
		d = c;
		c = b;
		b = a;
		a = T1 + T2;

		j++;
	} while(j < 64);

	/* Compute the current intermediate hash value */
	context->state[0] += a;
	context->state[1] += b;
	context->state[2] += c;
	context->state[3] += d;
	context->state[4] += e;
	context->state[5] += f;
	context->state[6] += g;
	context->state[7] += h;

	/* Clean up */
	a = b = c = d = e = f = g = h = T1 = T2 = 0;
}

#endif /* SHA2_UNROLL_TRANSFORM */

void sr_SHA256_Update(SHA256_CTX *context, const sha2_byte *data, size_t len)
{
	unsigned int freespace, usedspace;

	if(len == 0) {
		/* Calling with no data is valid - we do nothing */
		return;
	}

	/* Sanity check: */
	assert(context != (SHA256_CTX *)0 && data != (sha2_byte *)0);

	usedspace = (context->bitcount >> 3) % SHA256_BLOCK_LENGTH;
	if(usedspace > 0) {
		/* Calculate how much free space is available in the buffer */
		freespace = SHA256_BLOCK_LENGTH - usedspace;

		if(len >= freespace) {
			/* Fill the buffer completely and process it */
			MEMCPY_BCOPY(&context->buffer[usedspace], data, freespace);
			context->bitcount += freespace << 3;
			len -= freespace;
			data += freespace;
			SHA256_Transform(context, (sha2_word32 *)context->buffer);
		} else {
			/* The buffer is not yet full */
			MEMCPY_BCOPY(&context->buffer[usedspace], data, len);
			context->bitcount += len << 3;
			/* Clean up: */
			usedspace = freespace = 0;
			return;
		}
	}
	while(len >= SHA256_BLOCK_LENGTH) {
		/* Process as many complete blocks as we can */
		SHA256_Transform(context, (sha2_word32 *)data);
		context->bitcount += SHA256_BLOCK_LENGTH << 3;
		len -= SHA256_BLOCK_LENGTH;
		data += SHA256_BLOCK_LENGTH;
	}
	if(len > 0) {
		/* There's left-overs, so save 'em */
		MEMCPY_BCOPY(context->buffer, data, len);
		context->bitcount += len << 3;
	}
	/* Clean up: */
	usedspace = freespace = 0;
}

void sr_SHA256_Final(
		sha2_byte digest[SHA256_DIGEST_LENGTH], SHA256_CTX *context)
{
	sha2_word32 *d = (sha2_word32 *)digest;
	unsigned int usedspace;

	/* Sanity check: */
	assert(context != (SHA256_CTX *)0);

	/* If no digest buffer is passed, we don't bother doing this: */
	if(digest != (sha2_byte *)0) {
		usedspace = (context->bitcount >> 3) % SHA256_BLOCK_LENGTH;
#if BYTE_ORDER == LITTLE_ENDIAN
		/* Convert FROM host byte order */
		REVERSE64(context->bitcount, context->bitcount);
#endif
		if(usedspace > 0) {
			/* Begin padding with a 1 bit: */
			context->buffer[usedspace++] = 0x80;

			if(usedspace <= SHA256_SHORT_BLOCK_LENGTH) {
				/* Set-up for the last transform: */
				MEMSET_BZERO(&context->buffer[usedspace],
						SHA256_SHORT_BLOCK_LENGTH - usedspace);
			} else {
				if(usedspace < SHA256_BLOCK_LENGTH) {
					MEMSET_BZERO(&context->buffer[usedspace],
							SHA256_BLOCK_LENGTH - usedspace);
				}
				/* Do second-to-last transform: */
				SHA256_Transform(context, (sha2_word32 *)context->buffer);

				/* And set-up for the last transform: */
				MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);
			}
		} else {
			/* Set-up for the last transform: */
			MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);

			/* Begin padding with a 1 bit: */
			*context->buffer = 0x80;
		}
		/* Set the bit count: */
		MEMCPY_BCOPY(&(context->buffer[SHA256_SHORT_BLOCK_LENGTH]),
				&(context->bitcount), sizeof(sha2_word64));

		/* Final transform: */
		SHA256_Transform(context, (sha2_word32 *)context->buffer);

#if BYTE_ORDER == LITTLE_ENDIAN
		{
			/* Convert TO host byte order */
			int j;
			for(j = 0; j < 8; j++) {
				REVERSE32(context->state[j], context->state[j]);
				*d++ = context->state[j];
			}
		}
#else
		MEMCPY_BCOPY(d, context->state, SHA256_DIGEST_LENGTH);
#endif
	}

	/* Clean up state data: */
	MEMSET_BZERO(context, sizeof(*context));
	usedspace = 0;
}

char *sr_SHA256_End(
		SHA256_CTX *context, char buffer[SHA256_DIGEST_STRING_LENGTH])
{
	sha2_byte digest[SHA256_DIGEST_LENGTH], *d = digest;
	int i;

	/* Sanity check: */
	assert(context != (SHA256_CTX *)0);

	if(buffer != (char *)0) {
		sr_SHA256_Final(digest, context);

		for(i = 0; i < SHA256_DIGEST_LENGTH; i++) {
			*buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];
			*buffer++ = sha2_hex_digits[*d & 0x0f];
			d++;
		}
		*buffer = (char)0;
	} else {
		MEMSET_BZERO(context, sizeof(*context));
	}
	MEMSET_BZERO(digest, SHA256_DIGEST_LENGTH);
	return buffer;
}

char *sr_SHA256_Data(const sha2_byte *data, size_t len,
		char digest[SHA256_DIGEST_STRING_LENGTH])
{
	SHA256_CTX context;

	sr_SHA256_Init(&context);
	sr_SHA256_Update(&context, data, len);
	return sr_SHA256_End(&context, digest);
}


/*** SHA-512 SHA-512/256: *********************************************************/
void sr_SHA512_Init(SHA512_CTX *context)
{
	if(context == (SHA512_CTX *)0) {
		return;
	}
	MEMCPY_BCOPY(
			context->state, sha512_initial_hash_value, SHA512_DIGEST_LENGTH);
	MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH);
	context->bitcount[0] = context->bitcount[1] = 0;
}

void sr_SHA512_256_Init(SHA512_CTX *context)
{
	if(context == (SHA512_CTX *)0) {
		return;
	}
	MEMCPY_BCOPY(context->state, sha512_256_initial_hash_value,
			SHA512_DIGEST_LENGTH);
	MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH);
	context->bitcount[0] = context->bitcount[1] = 0;
}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-512 round macros: */
#if BYTE_ORDER == LITTLE_ENDIAN

#define ROUND512_0_TO_15(a, b, c, d, e, f, g, h)                      \
	REVERSE64(*data++, W512[j]);                                      \
	T1 = (h) + Sigma1_512(e) + Ch((e), (f), (g)) + K512[j] + W512[j]; \
	(d) += T1, (h) = T1 + Sigma0_512(a) + Maj((a), (b), (c)), j++


#else /* BYTE_ORDER == LITTLE_ENDIAN */

#define ROUND512_0_TO_15(a, b, c, d, e, f, g, h)           \
	T1 = (h) + Sigma1_512(e) + Ch((e), (f), (g)) + K512[j] \
		 + (W512[j] = *data++);                            \
	(d) += T1;                                             \
	(h) = T1 + Sigma0_512(a) + Maj((a), (b), (c));         \
	j++

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

#define ROUND512(a, b, c, d, e, f, g, h)                       \
	s0 = W512[(j + 1) & 0x0f];                                 \
	s0 = sigma0_512(s0);                                       \
	s1 = W512[(j + 14) & 0x0f];                                \
	s1 = sigma1_512(s1);                                       \
	T1 = (h) + Sigma1_512(e) + Ch((e), (f), (g)) + K512[j]     \
		 + (W512[j & 0x0f] += s1 + W512[(j + 9) & 0x0f] + s0); \
	(d) += T1;                                                 \
	(h) = T1 + Sigma0_512(a) + Maj((a), (b), (c));             \
	j++

void SHA512_Transform(SHA512_CTX *context, const sha2_word64 *data)
{
	sha2_word64 a, b, c, d, e, f, g, h, s0, s1;
	sha2_word64 T1, *W512 = (sha2_word64 *)context->buffer;
	int j;

	/* Initialize registers with the prev. intermediate value */
	a = context->state[0];
	b = context->state[1];
	c = context->state[2];
	d = context->state[3];
	e = context->state[4];
	f = context->state[5];
	g = context->state[6];
	h = context->state[7];

	j = 0;
	do {
		ROUND512_0_TO_15(a, b, c, d, e, f, g, h);
		ROUND512_0_TO_15(h, a, b, c, d, e, f, g);
		ROUND512_0_TO_15(g, h, a, b, c, d, e, f);
		ROUND512_0_TO_15(f, g, h, a, b, c, d, e);
		ROUND512_0_TO_15(e, f, g, h, a, b, c, d);
		ROUND512_0_TO_15(d, e, f, g, h, a, b, c);
		ROUND512_0_TO_15(c, d, e, f, g, h, a, b);
		ROUND512_0_TO_15(b, c, d, e, f, g, h, a);
	} while(j < 16);

	/* Now for the remaining rounds up to 79: */
	do {
		ROUND512(a, b, c, d, e, f, g, h);
		ROUND512(h, a, b, c, d, e, f, g);
		ROUND512(g, h, a, b, c, d, e, f);
		ROUND512(f, g, h, a, b, c, d, e);
		ROUND512(e, f, g, h, a, b, c, d);
		ROUND512(d, e, f, g, h, a, b, c);
		ROUND512(c, d, e, f, g, h, a, b);
		ROUND512(b, c, d, e, f, g, h, a);
	} while(j < 80);

	/* Compute the current intermediate hash value */
	context->state[0] += a;
	context->state[1] += b;
	context->state[2] += c;
	context->state[3] += d;
	context->state[4] += e;
	context->state[5] += f;
	context->state[6] += g;
	context->state[7] += h;

	/* Clean up */
	a = b = c = d = e = f = g = h = T1 = 0;
}

#else /* SHA2_UNROLL_TRANSFORM */

void SHA512_Transform(SHA512_CTX *context, const sha2_word64 *data)
{
	sha2_word64 a, b, c, d, e, f, g, h, s0, s1;
	sha2_word64 T1, T2, *W512 = (sha2_word64 *)context->buffer;
	int j;

	/* Initialize registers with the prev. intermediate value */
	a = context->state[0];
	b = context->state[1];
	c = context->state[2];
	d = context->state[3];
	e = context->state[4];
	f = context->state[5];
	g = context->state[6];
	h = context->state[7];

	j = 0;
	do {
#if BYTE_ORDER == LITTLE_ENDIAN
		/* Convert TO host byte order */
		REVERSE64(*data++, W512[j]);
		/* Apply the SHA-512 compression function to update a..h */
		T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] + W512[j];
#else  /* BYTE_ORDER == LITTLE_ENDIAN */
		/* Apply the SHA-512 compression function to update a..h with copy */
		T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] + (W512[j] = *data++);
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
		T2 = Sigma0_512(a) + Maj(a, b, c);
		h = g;
		g = f;
		f = e;
		e = d + T1;
		d = c;
		c = b;
		b = a;
		a = T1 + T2;

		j++;
	} while(j < 16);

	do {
		/* Part of the message block expansion: */
		s0 = W512[(j + 1) & 0x0f];
		s0 = sigma0_512(s0);
		s1 = W512[(j + 14) & 0x0f];
		s1 = sigma1_512(s1);

		/* Apply the SHA-512 compression function to update a..h */
		T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j]
			 + (W512[j & 0x0f] += s1 + W512[(j + 9) & 0x0f] + s0);
		T2 = Sigma0_512(a) + Maj(a, b, c);
		h = g;
		g = f;
		f = e;
		e = d + T1;
		d = c;
		c = b;
		b = a;
		a = T1 + T2;

		j++;
	} while(j < 80);

	/* Compute the current intermediate hash value */
	context->state[0] += a;
	context->state[1] += b;
	context->state[2] += c;
	context->state[3] += d;
	context->state[4] += e;
	context->state[5] += f;
	context->state[6] += g;
	context->state[7] += h;

	/* Clean up */
	a = b = c = d = e = f = g = h = T1 = T2 = 0;
}

#endif /* SHA2_UNROLL_TRANSFORM */

void sr_SHA512_Update(SHA512_CTX *context, const sha2_byte *data, size_t len)
{
	unsigned int freespace, usedspace;

	if(len == 0) {
		/* Calling with no data is valid - we do nothing */
		return;
	}

	/* Sanity check: */
	assert(context != (SHA512_CTX *)0 && data != (sha2_byte *)0);

	usedspace = (context->bitcount[0] >> 3) % SHA512_BLOCK_LENGTH;
	if(usedspace > 0) {
		/* Calculate how much free space is available in the buffer */
		freespace = SHA512_BLOCK_LENGTH - usedspace;

		if(len >= freespace) {
			/* Fill the buffer completely and process it */
			MEMCPY_BCOPY(&context->buffer[usedspace], data, freespace);
			ADDINC128(context->bitcount, freespace << 3);
			len -= freespace;
			data += freespace;
			SHA512_Transform(context, (sha2_word64 *)context->buffer);
		} else {
			/* The buffer is not yet full */
			MEMCPY_BCOPY(&context->buffer[usedspace], data, len);
			ADDINC128(context->bitcount, len << 3);
			/* Clean up: */
			usedspace = freespace = 0;
			return;
		}
	}
	while(len >= SHA512_BLOCK_LENGTH) {
		/* Process as many complete blocks as we can */
		SHA512_Transform(context, (sha2_word64 *)data);
		ADDINC128(context->bitcount, SHA512_BLOCK_LENGTH << 3);
		len -= SHA512_BLOCK_LENGTH;
		data += SHA512_BLOCK_LENGTH;
	}
	if(len > 0) {
		/* There's left-overs, so save 'em */
		MEMCPY_BCOPY(context->buffer, data, len);
		ADDINC128(context->bitcount, len << 3);
	}
	/* Clean up: */
	usedspace = freespace = 0;
}

void SHA512_Last(SHA512_CTX *context)
{
	unsigned int usedspace;

	usedspace = (context->bitcount[0] >> 3) % SHA512_BLOCK_LENGTH;
#if BYTE_ORDER == LITTLE_ENDIAN
	/* Convert FROM host byte order */
	REVERSE64(context->bitcount[0], context->bitcount[0]);
	REVERSE64(context->bitcount[1], context->bitcount[1]);
#endif
	if(usedspace > 0) {
		/* Begin padding with a 1 bit: */
		context->buffer[usedspace++] = 0x80;

		if(usedspace <= SHA512_SHORT_BLOCK_LENGTH) {
			/* Set-up for the last transform: */
			MEMSET_BZERO(&context->buffer[usedspace],
					SHA512_SHORT_BLOCK_LENGTH - usedspace);
		} else {
			if(usedspace < SHA512_BLOCK_LENGTH) {
				MEMSET_BZERO(&context->buffer[usedspace],
						SHA512_BLOCK_LENGTH - usedspace);
			}
			/* Do second-to-last transform: */
			SHA512_Transform(context, (sha2_word64 *)context->buffer);

			/* And set-up for the last transform: */
			MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH - 2);
		}
	} else {
		/* Prepare for final transform: */
		MEMSET_BZERO(context->buffer, SHA512_SHORT_BLOCK_LENGTH);

		/* Begin padding with a 1 bit: */
		*context->buffer = 0x80;
	}
	/* Store the length of input data (in bits): */
	MEMCPY_BCOPY(&(context->buffer[SHA512_SHORT_BLOCK_LENGTH + 0]),
			&(context->bitcount[1]), sizeof(sha2_word64));
	MEMCPY_BCOPY(&(context->buffer[SHA512_SHORT_BLOCK_LENGTH + 8]),
			&(context->bitcount[0]), sizeof(sha2_word64));

	/* Final transform: */
	SHA512_Transform(context, (sha2_word64 *)context->buffer);
}

void sr_SHA512_Final(
		sha2_byte digest[SHA512_DIGEST_LENGTH], SHA512_CTX *context)
{
	sha2_word64 *d = (sha2_word64 *)digest;

	/* Sanity check: */
	assert(context != (SHA512_CTX *)0);

	/* If no digest buffer is passed, we don't bother doing this: */
	if(digest != (sha2_byte *)0) {
		SHA512_Last(context);

		/* Save the hash data for output: */
#if BYTE_ORDER == LITTLE_ENDIAN
		{
			/* Convert TO host byte order */
			int j;
			for(j = 0; j < 8; j++) {
				REVERSE64(context->state[j], context->state[j]);
				*d++ = context->state[j];
			}
		}
#else
		MEMCPY_BCOPY(d, context->state, SHA512_DIGEST_LENGTH);
#endif
	}

	/* Zero out state data */
	MEMSET_BZERO(context, sizeof(*context));
}

char *sr_SHA512_End(
		SHA512_CTX *context, char buffer[SHA512_DIGEST_STRING_LENGTH])
{
	sha2_byte digest[SHA512_DIGEST_LENGTH], *d = digest;
	int i;

	/* Sanity check: */
	assert(context != (SHA512_CTX *)0);

	if(buffer != (char *)0) {
		sr_SHA512_Final(digest, context);

		for(i = 0; i < SHA512_DIGEST_LENGTH; i++) {
			*buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];
			*buffer++ = sha2_hex_digits[*d & 0x0f];
			d++;
		}
		*buffer = (char)0;
	} else {
		MEMSET_BZERO(context, sizeof(*context));
	}
	MEMSET_BZERO(digest, SHA512_DIGEST_LENGTH);
	return buffer;
}

char *sr_SHA512_Data(const sha2_byte *data, size_t len,
		char digest[SHA512_DIGEST_STRING_LENGTH])
{
	SHA512_CTX context;

	sr_SHA512_Init(&context);
	sr_SHA512_Update(&context, data, len);
	return sr_SHA512_End(&context, digest);
}


/*** SHA-384: *********************************************************/
void sr_SHA384_Init(SHA384_CTX *context)
{
	if(context == (SHA384_CTX *)0) {
		return;
	}
	MEMCPY_BCOPY(
			context->state, sha384_initial_hash_value, SHA512_DIGEST_LENGTH);
	MEMSET_BZERO(context->buffer, SHA384_BLOCK_LENGTH);
	context->bitcount[0] = context->bitcount[1] = 0;
}

void sr_SHA384_Update(SHA384_CTX *context, const sha2_byte *data, size_t len)
{
	sr_SHA512_Update((SHA512_CTX *)context, data, len);
}

void sr_SHA384_Final(
		sha2_byte digest[SHA384_DIGEST_LENGTH], SHA384_CTX *context)
{
	sha2_word64 *d = (sha2_word64 *)digest;

	/* Sanity check: */
	assert(context != (SHA384_CTX *)0);

	/* If no digest buffer is passed, we don't bother doing this: */
	if(digest != (sha2_byte *)0) {
		SHA512_Last((SHA512_CTX *)context);

		/* Save the hash data for output: */
#if BYTE_ORDER == LITTLE_ENDIAN
		{
			/* Convert TO host byte order */
			int j;
			for(j = 0; j < 6; j++) {
				REVERSE64(context->state[j], context->state[j]);
				*d++ = context->state[j];
			}
		}
#else
		MEMCPY_BCOPY(d, context->state, SHA384_DIGEST_LENGTH);
#endif
	}

	/* Zero out state data */
	MEMSET_BZERO(context, sizeof(*context));
}

char *sr_SHA384_End(
		SHA384_CTX *context, char buffer[SHA384_DIGEST_STRING_LENGTH])
{
	sha2_byte digest[SHA384_DIGEST_LENGTH], *d = digest;
	int i;

	/* Sanity check: */
	assert(context != (SHA384_CTX *)0);

	if(buffer != (char *)0) {
		sr_SHA384_Final(digest, context);

		for(i = 0; i < SHA384_DIGEST_LENGTH; i++) {
			*buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];
			*buffer++ = sha2_hex_digits[*d & 0x0f];
			d++;
		}
		*buffer = (char)0;
	} else {
		MEMSET_BZERO(context, sizeof(*context));
	}
	MEMSET_BZERO(digest, SHA384_DIGEST_LENGTH);
	return buffer;
}

char *sr_SHA384_Data(const sha2_byte *data, size_t len,
		char digest[SHA384_DIGEST_STRING_LENGTH])
{
	SHA384_CTX context;

	sr_SHA384_Init(&context);
	sr_SHA384_Update(&context, data, len);
	return sr_SHA384_End(&context, digest);
}
